Tony Z. Qiu

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With the dramatic development of image processing technology, a growing number of traffic flow detection and analyses have been conducted by using video data. Time to collision (TTC) and postencroachment time (PET) are two major parameters used to indicate the severity of a potential collision and to capture an imminent vehicular accident. However,(More)
The METANET model, deduced based on equilibrium state assumption, provides a candidate model for freeway traffic control design since it has both speed and density dynamics, but the previous work parameterized the speed control variable to be highly nonlinear, which caused difficulty in control design and implementation. Besides, the model could not catch(More)
Accurate queue estimation of traffic congestion at recurrent freeway bottlenecks is an important part of developing effective traffic control strategies. Two traffic flow analytical techniques are always employed in studying queuing processes: shockwave analysis and input-output analysis. These two techniques have been taken as separate tools for estimating(More)
Transportation agencies are moving toward the development of enterprise-wide transportation infrastructure system (TIMS) or Transportation Asset Management System (TAMS). This is an opportune time to include geometric design and safety-based applications within the overall TIMS development. Alberta Transportation commenced the development of TIMS in 1996.(More)
Roadside equipment (RSE) is a key component to collect/disseminate information from/to vehicles in a Connected Vehicle (CV) environment. It plays different roles in various safety, mobility and environmental applications. In the future, millions of RSE can be deployed on urban streets and highways. At the initial stage of CV development, however, it may be(More)
Freeway congestion is highly recognized as a worldwide traffic problem since traffic demand has grown steadily over the past decades. Active traffic and demand management (ATDM) methods, including Ramp Metering (RM), Variable Speed Limit (VSL), and Route Guidance (RG), can help delay or even avoid congestion. Currently, those measures have become predictive(More)
In this paper various theories on traffic jams and stop-and-go wave modeling were reviewed and discussed. These include traditional microscopic car-following model, asymmetric traffic theory, first-order and second-order macroscopic models, traffic disturbance model, phase transition model as well as macroscopic simulation. The mechanism of stop-and-go(More)
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